Yarn is useful in constructing many articles, for example yarn that is used in the tufting industry for the tufting of carpets. Prior to its use, it is desirable to heat treat and set the yarn.
In making yarn, fibers are arranged parallel to each other by machinery and drawn into rather bulky loose strands, which are repeatedly twisted, lengthened for further straightening and orienting the fibers parallel to each other, and combining of strands. During this process, the yarn filaments or strands are pulled relative to each other, untangled, and operated upon at increasing speeds by machinery, so that it has become the practice to treat the strands, particularly synthetic fibers that do not have natural oils, with lubricating oils to facilitate relative movement of strands and to further treat them with anti-static agents to further facilitate their movement with respect to each other and with respect to the machinery operating upon them.
In recent years, a plurality of various pressure and heat treating machinery, with corresponding spooling and unspooling devices have been replaced by a single machine that can operate upon a plurality of yarn strands coming from the above-mentioned treatment to process the yarn prior to its dyeing or use. In this apparatus, the yarn is heat treated at relatively high temperatures with steam. This steam treatment vaporizes and drives off the various working fluids, such as lubricating oils and anti-static liquids that are on the yarn when the yarn enters the apparatus. These vapors then condense on the surfaces that they come in contact with or are completely exhausted. For exhausting the spent steam, various pipes and a blower are provided, which structure forms surfaces that will condense the vapors. Some of the condensate forms a mat-like mass with the unavoidably present airborn yarn filament pieces and the condensate at least partially solidifies at the high temperatures within the apparatus. This mat progressively reduces the through flow cross sectional areas of the pipes removing the spent steam, to produce pressure losses causing increased difficulty in removing the spent steam, increased difficulty in maintaining the temperature for the yarn treatment, which is critical, and increasing temperature and pressure variations throughout the system over what is desirable.
It has been the practice in the past to disassemble the blower and all the pipes providing for the removal of the spent steam and remove the mats on their interior surfaces by hand scraping, high pressure fluids, and the like at a location remote from the treating apparatus. Further, it has been the practice to place small men within the enclosure of the apparatus to scrape the interior surfaces. It is common to operate this machine 24 hours a day, 7 days a week, except for maintenance. The above described cleaning operation is usually done between each week and each month, and it takes approximately 8 hours for a multi-person crew to perform each cleaning.
Examples of yarn treating machines are disclosed in U.S. Pat. No. 3,426,553 and U.S. Pat. No. 3,683,650.